Impairment to left ventricular (LV) filling can result from left-sided cardiovascular conditions proximal to the left ventricle (mitral stenosis, cortriatriatum, pulmonary venous obstruction), from LV myocardial conditions (including hypertrophic cardiomyopathy, amyloidosis and hemosiderosis), from pericardial constriction (of several etiologies), and from LV endomyocardial fibrosis with or without eosinophilia. The latter condition, occurring primarily in Africa, causes extensive LV endocardial fibrosis located primarily in the LV inflow tract and is associated with little or no mural endocardial calcific deposits. The common denominator of all these conditions is a normal sized or samll LV cavity. This report describes a hitherto unreported cause of impairment to LV filling, namely massive LV endocardial calcific deposits associated with LY hypertrophy of undetermined etiology. The cause of the LV mural endocardial calcific deposits and the associated LV hypertrophy in the above described patient is uncertain. The lack of blood eosinophilia at any time, the presence of considerable LV hypertrophy, and the presence of the extensive, widely distributed calcific deposits within the LV cavity clearly separates our patient from those having "endomyocardial fibrosis with or without eosinophilia" or "Loffler's fibroplastic parietal endocarditis." Irrespective of its cause, however, the entity, massive LV endocardial calcific deposits, needs to be added to the list of causes producing impairment of LV filling.